1. Field of the Invention
This invention relates to a liquid crystal display, and more particularly to a liquid crystal display device and a method of fabricating a liquid crystal display device that prevents the liquid crystal from being blended with a sealant during liquid crystal injection.
2. Discussion of the Related Art
Generally, a liquid crystal display (LCD) device controls the light transmissivity of liquid crystal cells arranged in a matrix in response to video signals, thereby displaying a picture corresponding to the video signals on a liquid crystal display panel. To this end, the LCD device includes an active area having the liquid crystal cells arranged in a matrix and driving circuits for driving the liquid crystal cells of the active area.
More specifically, the LCD device includes a lower plate, an upper plate, spacers provided between the upper plate and the lower plate to assure a constant cell gap, and a liquid crystal filled in the space defined by the spacers between the upper and lower plates. The lower plate has thin film transistors, for switching the liquid crystal cells, driving circuits for driving the thin film transistors, and signal lines connected between the driving circuits and the thin film transistors mounted onto a lower substrate. The upper substrate is provided with a Black matrix, color filters and a common electrodes disposed sequentially. The color filters each has any one of red, blue and green colors. Such a LCD device is fabricated by separately forming the upper and lower plates, joining the upper and lower plates to each other, injecting a liquid crystal through liquid crystal injection holes provided at the side surface of the structure, coating the liquid crystal injection holes with a end sealant, and curing the end sealant.
A recent liquid crystal injection method that has been developed and widely used is the dispensing method. The dispensing will be described below with reference to FIGS. 1A to 1E and FIGS. 2A to 2B.
FIGS. 1A to 1E schematically show a process of injecting a liquid crystal between the upper plate 2 and the lower plate 1 of the LCD device. First, as shown in FIG. 1A, thin film transistors, gate lines, data lines, pixel electrodes, and an alignment layer (not shown) are provided on a lower plate 1 of the LCD device. Similarly, common electrodes, color filters, black matrix and an alignment layer (not shown) are provided on an upper plate 2 of the LCD device. Then, a sealant 3 is coated on the lower plate 1 to form a frame. As shown in FIG. 1B, a liquid crystal 5 is formed on the lower plate 1 provided within the frame using a liquid crystal dispenser 4. As shown in FIG. 1C, the front side of the lower plate 1 having the liquid crystal 5 is covered with the upper plate 2. Then, as shown in FIG. 1D, heat and pressure 6, are applied to the upper plate 2 to press the upper plate 2 toward the lower plate 1. When the pressure 6 is applied, the liquid crystal 5 spreads and blends with the sealant 3 as seen from portion “A” of FIG. 1E, thereby causing interference problems. Therefore, liquid crystal penetrates into the lower portion of the sealant as seen from portions “B” and “C” of FIGS. 2A and 2B, thereby causing an insufficient liquid crystal injection phenomenon as well as generating a stain at the periphery of the sealant due to liquid crystal contamination at a contact surface between the sealant and the liquid crystal.